Car engine won't run smooth after being parked for 7 years

I’ve totally cleaned the carburetor but the engine still runs bad from the gas (1/2 tank still) that sat there for 7 years. I’m told it will run good/smooth again once the old gas is consumed and it begins using new fresh gas. My question is this: IS THERE SOME ADDITIVE THAT WILL HELP SIGNIFICANTLY, IN THE MEANTIME?

dont run this gas in your motor! drain it, and try to put some plugs in it

siphon out old gas and add new gas

by the way how did you even get this to start???

what kind of car? yr, etc

What kind of car? Most imports have a drain plug underneath. GET THAT OLD GAS OUT!! It is stale, most likely varnished, and trouble for the fuel system. Also, replace the spark plugs.

Please drain that gasoline, for now if you have run that car, you may need new gas filter, it is time for spark plugs, if your will come out, hope you changed the oil and filter and you will have to clean the carburetor. You should also replace the transmission fluid and brake fluid to be in the safe side. Do not drive it until you check the brakes to avoid a trip to the ER. What car is that anyway?

You’re going to have to spend some time on this vehicle,whatver it is.
Drain the tank, blow out the fuel lines,replace the fuel filter, and you can safely bet that the carburetor will have to be overhauled. After 7 years, gaskets, O-rings, and the accelerator pump diaphragm will be dried out and unuseable.

It’s always possible the fuel tank may need replacement due to condensation causing rust in the tank, especially if the car was sitting outside.